The present invention relates to sprinkler units and pertains particularly to an improved sprinkler nozzle having improved range of the water stream.
The artificial distribution of water through irrigation systems is in wide use throughout the world today. There are many irrigation systems utilized, with each having its benefits and drawbacks.
One of the most widely used systems, particularly where water is not abundant or plentiful, is the sprinkler system wherein a plurality of nozzles are distributed about an area for distributing water over the surface of the land area. Such systems are widely used for lawns, golf courses, playing fields and many field crops.
The ideal sprinkler irrigation system would utilize a minimum number of nozzles to achieve a substantially uniform distribution of water over a maximum area. This approach presents a major problem since the optimum reach, or distance to which a given volume of water is thrown, of a sprinkler unit is inconsistent with optimum distribution. Optimum reach of a sprinkler unit is achieved by maintaining a coherent or homogenous water stream. A coherent or homogenous stream would distribute most of the water at the outermost end of its reach.
One approach is disclosed in U.S. Pat. No. 4,796,809, granted Jan. 10, 1989 to Edwin J. Hunter.
In order to obtain a coherent or homogenous water stream, turbulence must be eliminated at the nozzle outlet. The majority of turbulence at the nozzle outlet is caused by curves in the water passage near the outlet for directing the vertical flow from the vertical riser to the horizontal direction of the outlet. This turbulence can be largely eliminated with large diameter units by providing a long straight passage from the curve of the passage to the outlet. However, this approach is not possible with small diameter sprinkler units.
For a rotating stream sprinkler unit having a coherent stream, the majority of the water would be distributed in a circular path at the outermost reach of the stream, forming a circle surrounding the sprinkler unit. In order to cover the area inside the circle toward the center of axis of rotation, it is necessary to disrupt the stream to cause deflection of a portion of the stream over the inner area. Many attempts have been made in the past to provide an optimum mechanism for achieving an optimum distribution of water over the area. While many of these attempts have proven to be somewhat effective, they have not been entirely satisfactory.
Accordingly, it is desirable that a sprinkler nozzle be available for providing optimum reach for a given stream of water from a sprinkler unit to provide optimum water coverage.